(a\a@-1)+(3a+1\a@-1)+(2a+3\1-a@)化简,@代表平方.

问题描述:

(a\a@-1)+(3a+1\a@-1)+(2a+3\1-a@)化简,@代表平方.

(a\a@-1)+(3a+1\a@-1)+(2a+3\1-a@)
=a/[(a+1)(a-1])+(3a+1)/[(a+1)(a-1)+(2a+3)/[(1-a)(1+a)]
=(a+3a+1-2a-3)/(a+1)(a-1)
=(2a-2)/(a+1)(a-1)
=2/(a+1)